As sizes of electronic parts and components decrease continuously and performance and speeds of the electronic parts and components improve gradually, energy consumption and heating power consumption of chips are increasingly high. Heat dissipation condition of the electronic parts and components and temperature evenness on surfaces of the electronic parts and components directly affect performance and long-term reliability of the electronic parts and components. A fan heat sink is a conventional heat dissipation manner. With information and communication technologies fusion, as power consumption of communications devices increases continuously, fan cooling is improved in aspects such as a rotation speed and a size. However, for fan cooling, a heat dissipation capability cannot be enhanced without limit, and a conspicuous noise problem arises. Therefore, development of a liquid cooling technology can make up such a disadvantage. Currently, the liquid cooling technology has been applied in multiple fields such as data centers, servers, and personal computers (PCs).
An existing heat dissipation apparatus mainly includes a main water pipe and multiple branch water pipes connected to the main water pipe, where boards are mounted on the branch water pipes.
However, when a board is mounted on a branch water pipe or a board is removed from a branch water pipe, a flow capacity of coolant in the main water pipe cannot be controlled. If there is a small quantity of boards, a flow capacity of coolant flowing through each board is relatively large. In this case, a proportional valve needs to be controlled to adjust temperature of coolant in the branch water pipe, so as to change the temperature relatively greatly. A relatively large temperature change results in problems of decreasing performance and service life of the heat dissipation apparatus, reducing stability of the heat dissipation apparatus.